Printing matrix made by a colloid transfer process



1966 1'. l. ABBOTT I 3,276,871

PRINTING MATRIX MADE BY A COLLOID TRANSFER PROCESS Filed March 4, 1965 2 Sheets-Sheet 1 {UNHARDENED GELATINOSILVER HALIDE LIGHT-SENSITIVE LAYER POLYMER LAYER CONTAINING PIGMENT 7 II AND TANNING DEVELOPER I0 "SUPPORT UNHARDENED GELATINO SILVER HALIDE LIGHT-SENSITIVE LAYER l5 CONTAINING PIGMENTAND TANNING DEVELOPER CELLULOSE ETHER LAYER CONTAINING PIGMENT AND TANNING DEVELOPER r-SLIPPORT ThomasLAbbo it IN V EN TOR.

Oct. 4, 1966 'r. I. ABBOTT 3,276,871

PRINTING MATRIX MADE BY A COLLOID TRANSFER PROCESS Filed March 4, 1965 2 Sheets-Sheet 2 LIGHT EXPOSURE (I; SUBJECT x I Sta -Q UNHARDENED GELATINO- SILVER HALIDE LIGHT-SENSITIVE LAYER CELLULOSE ETHER *GELATIN LAYER coNTAININe PIGMENT AND TANNING DEVELOPER I41. A CELLULOSE ETHER LAYER CONTAINING PIGMENTAND TANNING DEVELOPER l3{ s U P PO R T EXPOSED, DEVELOPED AND HARDENED GELATINO-SILVER RESIST 2o RECEIVING SHEET FOR UNEXPOSED AND UNDEVELOPED SILVER HALIDE H /%\-RESIST IMAGE RESERVOIR FOR PIGMENT I." "2 1.5% SUPPORT Thomas I. Abb 0 it IN V EN TOR.

BY @ZMM manners United States Patent 3,276,871 PRINTING MATRIX MADE BY A COLLOID TRANSFER PROCESS Thomas I. Abbott, Rochester, N.Y., assignor to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey Filed Mar. 4, 1965, Ser. No. 440,671 20 Claims. (Cl. 96-28) This is a continuation-impart of application 194,305 filed May 14, 1962, now abandoned.

The present invention concerns photography, and more particularly, photosensitive plates suitable for preparing printing matrixes and processes for preparing such.

There are several photosensitive printing or duplicating elements known in the art. In one such photosensitive printing element, the printed image is obtained by dissolving a dye in alcohol. However, this process has many of the characteristics common to spirit duplicating systems in that feathering often results. Moreover, since the most desirable dye for use with this process is the purple commonly seen in copies of this type, this method is not always suitable for reproductions. Moreover, the spirit duplicating system can only be used with a line copy since there are no intermediate levels of reproduction such as might be obtained in the printing art using a halftone screen or a continuous tone printing plate.

In still another photomechanical spirit duplicating process, a frangible polymer layer is coated over a dye layer, which is then contacted against a moist adhesive photographic image. The frangible layer adheres to the adhesive areas of the photographic element exposing an area of the spirit duplicating medium which then is used for producing an image using alcohol, which dissolves the dye. As in the conventional spirit duplicating process, problems result in handling the spirit duplicating master, feathering, etc.

Various improvements have been suggested for providing a photographic spirit duplicating system. However, many of the resulting products I ave such limitations as low sensitivity to light, inability to reproduce sharp images, inability to make more than a few copies of good quality, and other related undesirable features.

There has also been a development in the printing art requiring the use of magnetic particles in printing ink. The printed images which are prepared with particular magnetic properties can be scanned by automatic equipment for such information as account numbers and branch bank numbers when these printed images are used on checks or the like. For most known printing procedures used in obtaining magnetic printed images, the magnetic characters are printed with lithography. However, it has been desirable to find a method of printing more easily than by lithography to obtain these magnetic printed images which could then be used with the available automatic scanning equipment.

I have discovered a photographic system which obviates many of the undesirable features that characterize prior art photosensitive printing plates and photomechanical duplicating or copying methods. This system provides sharper images, absence of feathering, permanent images, reproduction of gray areas, magnetic images, etc.

It is an object of this invention to provide :a novel photosensitive printing element.

It is another object of this invention to provide a new process for preparing a pre-inked printing matrix.

It is still another object of this invention to provide a novel photomechani-cal process for duplicating a plurality of sharp images.

These and other objects are attained by means of this invention as described more fully hereinafter with refer- "ice ence to preferred embodiments thereof as illustrated in the drawings and in the examples.

In general, the present invention concerns a photosensitive element comprising a support, at least one layer coated over the support comprising an organic solventsoluble polymer substrate containing an inert pigment and a tanning developing agent, and coated thereover a photographic gelatino-silver halide emulsion.

FIGURE 1 and FIGURE 2 of the drawings are fragmentary sectional views illustrating photosensitive printing elements of the invention.

FIGURE 3 of the drawings illustrates in section and schematically three typical stages of the process of the invention for utilizing a photosensitive element such as illustrated by FIGURE 2 to prepare a printing matrix.

With respect to the photosensitive element of FIGURE 1, polymer layer 11 containing a pigment and a tanning developing agent is coated on support 10. Overcoated on polymer layer 11 is photosensitive unhardened gelatino-silver halide layer 12. Polymer layer 11 serves as a reservoir for pigment material to be utilized in mechanically reproducing images with photosensitive elements of the invention. Polymer layer 11 also serves as a reservoir for tanning developer which can be activated by immersing the element in an aqueous alkaline medium.

FIGURE 2 is a drawing of another typical photosensitive element of the invention. On support 13 is coated cellulose ether layer 14. Over cellulose ether layer 14 is coated cellulose ether-gelatin layer 15. Both layer 14 and layer 15 serve as reservoirs for pigment and tanning developing agents. Over layer 15 is coated photosensitive unhardened gelatino-silver halide layer 16.

FIGURE 3 of the drawings schematically illustrates the processing of the element of FIGURE 2 in accordance with the invention. In Stage 1 of the process, photosensitive unhardened gelatino-silver halide layer 16 is exposed by light through subject 17 to produce a latent image in layer 16. The resulting exposed element is developed in an aqueous alkaline solution which activates the tanning developing agent in layers 14 and 15 to develop silver halide in the exposed portions of layer 16 to form hardened or tanned gelatino-silver resist image layer 18 as shown in Stage 2 which defines a negative-image area. Unexposed and undeveloped area 19 of layer 16 is thereafter readily stripped out by removing excess water from the surface thereof and pressing in contact therewith, while undeveloped area 19 is still moist, an absorbent grease-free or hydrophilic surface such as receiving sheet 20. On removal of receiving sheet 20, unexposed :and undeveloped silver halide 19 is removed or stripped out, leaving hardened gelatino-silver resist image 18 as shown in Stage 3. On removal of such unexposed and undeveloped silver halide from the element, cellulose ether-gelatin layer 15 is exposed to the surface to form a positive image area. The resulting element can then be utilized as :a matrix to print positive copies of subject 17 by first supplying a suitable organic solvent for the cellulose ether and pressing successive receiving sheets against the element and transferring a portion of the pigment in layers 14 and 15 to such receiving sheet. Such prepared matriXes can be utilized, .for example, on a multilith press without ink to prepare copies.

The tanning developing agents that can be suitably incorporated in the photosensitive elements of the invention can be of a wide variety. The subject developing agents are typically substantially Water-insoluble developing agents which tan the gelatin carrier for the silver halide upon development in an alkaline solution.

Examples of tanning developing agents specially useful because of their non-wandering characteristics, high rate of development, high tanning efliciency and solubility in the preferred range, are those having a solubility of from about .005 to 1.0 gram per 100 cc. of a phosphate citric acid bulfer solution of pH 5.0 prepared from a 1.5% solution of sodium dihydrogen phosphate and sufficient citric acid to bring the pH to 5.0. Dihydroxy diphenyl tanning developers are particularly useful.

Illustrative suitable tanning developing agents include 3,4-dihydroxy diphenyl, 2,5-dihydroxy diphenyl, 5,6,7,8- tetrahydronaphthohydroquinone, 2,3-dihydroxy diphenyl, methyl pyrocatechol, methyl gentisate, gentisaldehyde, 4- tertiary butyl catechol, 3-methoxy catechol, 4-hexylpyrogallol, 2-phenoxy hydroquinone, and the like. Reference is made to Yackel, U.S. Patent No. 2,592,368 dated April 8,1952, and Yackel, U.S. Patent No. 2,685,51O dated August 3, 1954, with respect to suitable tanning developing agents and their incorporation and use in photographic layers.

The tanning developing agent'can be incorporated in the layers of the present elements with the aid of a solvent in accordance with usual practice. Also, tanning developing agents having low solubility (e.g. 4-phenyl catechol) can he ball milled in water to produce slurries which can be incorporated into aqueous gelatin compositions without utilizing a solvent. The tanning developing agent is dispersed in the polymeric sublayers of the present elements to produce matrixes useful for printing sharp images. This disposition of the developing agents provides a harder resist than can be obtained when the developing agents are used in the gelatino-silver halide emulsion overcoat layer, and further, it is useful in the elimination of an otherwise necessary drying step between strip out and printing. Sufficient developing agent is incorporated in the subject elements to develop the silver halide in the overcoat layeron exposure thereof.

The photosensitive layer, the overcoat layer, on the .subject photosensitive elementcomprises an unhardened gelatino-silver halide emulsion. Silver chloride emulsions are particularly useful, although other silver halide emulsions such as silver bromide, silver chloroiodide, silver chlorobromide, silver chlorobromoiodide and silver bromoiodide emulsions can also be suitably utilized. The gelatino-silver halide emulsion layer is not harder than a gelatin layer containing about 0.7 gram of formaldehyde per pound of gelatin freshly coated. The gelatin substrate of the photosensitive layer is coated so as to have a coverage of about 5Q to 150 mg. of gelatin per square foot when dry. The gelatin coverage in the photosensitive layer is controlled between such limits to facilitate complete removal of unexposed and undeveloped gelatinosilver halide emulsion during the stripping-out step described above to expose the pigment dispersed in the polymeric substrate below.

The pigment utilized in the elements of the invention as built-in ink materials includes a wide variety of coloring materials. Suitable coloring materials are carbon black, ultra-marine blue, Nigrosine dyes, copper phthalocyanine dye, and the like. .The pigment is utilized .only in the subcoatings and not in the photosensitive overcoat layer, this resulting in the printing of particularly sharp images with matrixes prepared in accordance with the invention. Also, the present photoelements are more sensi tive to light than photoelements having the pigment dispersed in silver halide, emulsion layers.

The pigment may be a magnetic pigment either in whole or in part. For instance, a mixture of carbon black and a magnetic pigment may be used. In one useful embodiment, magnetite (Fe O may be used at a coverage of 1.542 g./ft. Magnetite is also described as a ferrosoferric oxide. Other ferro-magnetic iron oxides may. be used, including gamma ferric oxide (Fe O and other magnetic particles which possess the ability to become permanently magnetized, i.e. particles having a high-magnetic susceptibility. In addition, the ferro-magnetic particles useful in this invention can be those having a high magnetic permeability. Magnetic particles of nickel, cobalt, and iron are useful for this purpose. A particularly useful material is carbonyl iron, containing iron obtained in particles having a diameter as small as 3 microns from iron carbonyl. However, larger particles can be used depending upon the fineness of detail desired in the image. Carbonyl Iron, Type G, sold by the. General Aniline and Film Corporation, is our preferred material. It is about 98 percent pure and has a weight-average diameter of about 8 microns, and is spherically formed.

It will be appreciated that the quantity of pigment and/or magnetic material which is used is not critical but depends upon the desired effect. For some purposes, the magnetic particles will be of particular interest so that the printed image can be sensed .or read by automated equipment, such as in banking applications where the magnetic image is used on checks and related records. It may be desirable to incorporate a small amount of pigment in these magnetic adaptations to provide additional density to the image areas. For certain uses, the pigment may be used solely for the purpose of supplying density and to obtain a sharp image.

Although specific reference has been made to Fe, Co, and Ni particles, it will be realized that certain other magnetic materials such as certain complex ions, coordination compounds, alloys, nitrogemcontaining polymers, etc. which have the special properties as herein described, may be utilized as magnetic pigments.

The polymeric substrate beneath the photosensitive layer of the subject photosensitive elements is comprised essentially of an oleophilic polymeric material that can be solubilized with an organic solvent which does not substantially affect the hardened gelatino-silver resist image produced in the present process. The polymeric layer or layers beneath the photosensitive layer serves as a reservoir for the pigment, and which pigment is brought to the surface for transfer to a receiving sheet for producing an image in the presence of an organic solvent which solubilizes the polymeric material having the pigment dispersed therein, and which solvent is applied to the matrix prepared in accordance with the invention at the time of printing.

I have found that cellulose polymers such as cellulose ethers are particularly suitable for the subjectsublayers. Other suitable polymeric substrates include polyvinyl chloride acetates, polyvinyl chloride butyrals, polyvinyl chloride acetals, polyvinyl chloride formals, polystyrenes, polymethacrylates, polyacrylates, and related polymeric compositions.

Gelatino-silver halide emulsion layers such as the present photosensitive overcoat layers tend to have poor adhesion to oleophilic layers such as cellulose ether layers. I have found that a minor proportion of gelatin mixed with the oleophilic polymeric materialimproves the adherence of the gelatino-silver halide emulsion layer thereto, and particularly the adherence of the hardened or tanned gelatino-silver resist image thereon during the utilization of the subject elements for printing. Generally, from about 10% to 40% by weight of gelatin based on the combined weight of the gelatin and the oleophilic polymer are utilized in the layer immediately below the photosensitive gelatino-silver halide layer.. In a preferred embodiment of the invention, as illustrated by the element of FIGURE 2, more than one layer is utilized beneath the photosensitive layer. In the element of FIGURE 2 a cellulose ether-gelatin layer is positioned immediately below the photosensitive layer, and the cellulose ether layer is positioned beneath the cellulose ether-gelatino layer for purposes of incorporating additional pigment material in the element.

After exposure of the photosensitive elements of the invention, aqueous alkaline solutions are utilized to activate the tanning developer in the present elements in accordance with usual practice. Such alkaline solutions desirably have a pH of at least 10, although the alkalinity of the developing solution can be widely varied in accord-. ance with usual practice, the higher alkalinities serving to reduce the processing time. Alkaline materials such as alkali metal carbonates and hydroxides including sodium carbonate, sodium hydroxide, potassium carbonate, p0- tassium hydroxide, and the like, can be suitably employed as alkaline materials in such activating or processing solutions.

The printing matrix prepared in accordance with the invention contains on the surface thereof a gelatino-silver resist negative area and an exposed sublayer of polymeric material as a positive image area, the polymeric material serving as a reservoir for the pigment or ink utilized in the printing process. No additional ink or related material need be utilized to make prints with the present printing matrixes. To liberate or free the pigment in the positive image area for printing, the surface of the matrix is moistened with a solvent for the polymeric substrate containing the pigment. Organic solvents that are at least as waterimmiscible or oleophilic as n-butanol are utilized. If the solvent is too miscible with water, the gelatino-silver resist tends to dissolve. Useful organic solvents include ether alcohols and ether acetates such as 2-(2-butoxyethoxy) ethyl acetate, as well as such solvents as cyclohexanol, N-butyl acetanilide, di(tetrahydrofural) adipate, and the like,

A wide variety of photographic supports can be utilized in preparing the photosensitive elements of the invention. I prefer to utilize conventional photographic supports such as could be utilized in conjunction with multilith and related duplicating equipment. Suitable supports include paper, polyethylene film, cellulose acetate film, polystyrene film, cellulose nitrate film, polyvinyl acetal film, polyethylene terephthalate film, and the like.

The invention is further illustrated by the following examples of preferred embodiments thereof.

Example 1 A two-layer photosensitive element of the type illustrated by FIG. 1 was prepared on a polyethylene support. A dispersion containing essentially ethyl cellulose, gelatin, finely divided carbon particles and 4-phenyl catechol in tricresyl phosphate was coated on the support at 10.0 cc. per square foot, the resulting dried coating containing:

Addenda: Concentration mg./ft. Carbon 495 Ethyl cellulose 216 Gelatin 130 4-phenyl catechol 113 Tricresyl phosphate 226 In preparing the dispersion used in the above-described carbon-containing coating, the ethyl cellulose and the 4- phenyl catechol were ball milled for 16 hours in toluene and tricresyl phosphate and thereafter the resulting mixture was mixed at high speed in a blender with the gelatin. Thereafter a gelatino-silver chloride emulsion was coated over the above-described carbon-containing coating at a coverage of 91 mg. of gelatin per square foot and 98 mg. of silver per square foot when dried. The resulting photosensitive element was then exposed through a line positive for 1.5 seconds with a No. 2 photoflood bulb at 18 inches. The exposed element was then immersed for seconds in a 3% aqueous sodium carbonate bath at 82 F. to develop the image. A sheet of bond receiving paper was rolled in contact with the developed element, and substantially all unexposed and undeveloped silver halide in the photosensitive overcoat layer was transferred to the receiving paper and stripped oil leaving a matrix-containing a hardened or tanned gelatino-silver resist image. The resulting matrix was attached to the blanket of a multilith press, no ink being used. The surface of the matrix was wetted with organic solvent, 2-(2-butoxyethoxy) ethyl acetate, through the ink rollers and plate cylinder of the press. Approximately 3 cc. of the organic solvent was used for making sharp dense prints on sheets (8%" x 11") of printing paper. In the present duplication proc- Example 2 A three-layer photosensitive element of the type illustrated by FIG. 2 was prepared on a polyethylene support. The first layer contained essentially ethyl cellulose, finely milled carbon particles, 4-phenyl catechol, and sucrose acetate isobutyrate, and was coated on the support at 15.0 cc. per square foot, the resulting dried coating containing:

Addenda: Concentration mg./ft. Carbon 1,252 Ethyl cellulose 262 Sucrose acetate isobutyrate 1,042 4-phenyl catechol 262 Over the first layer was coated a second layer containing essentially carbon, ethyl cellulose, gelatin, and 4-phenyl catechol, the resulting dried coating containing:

Addenda: Concentration mg./ft. Carbon 290 Ethyl cellulose 215 Gelatin 150 4-phenyl catechol 84 The carbon particles utilized in the first and second layers described above were ball milled for 16 hours in toluene and thereafter mixed with the addenda of the respective layers at high speed in a blender. Thereafter, a gelatinosilver chloride emulsion containing a green sensitizing dye was coated over the above-described layers at 4.0 cc. per square foot to give mg. of silver per square foot and 102 mg. of gelatin per square foot when dried. The resulting photosensitive element was then exposed to a 20- second projection of a line original in a 1/ 1 camera with an f/22 lens opening, four No. 1 photoflood bulbs being used for illumination. The resulting exposed element was developed, and then unexposed and undeveloped silver halide stripped out as described in Example 1. The resulting matrix was afiixed in a multilith press, wetted with the organic solvent, 2-(2-butoxy-ethoxy) ethyl acetate, and a plurality of prints made as described in Example 1. Approximately 40 legible copies were prepared, with the first 25 copies being particularly sharp, dense prints.

Example 3 Addenda: Concentration mg./ft. Magnetite 1,252 Ethyl cellulose 262 Sucrose acetate isobutyrate 1,042 4-phenyl catechol 262 Over the first layer was coated a second layer containing essentially powdered magnetite, ethyl cellulose, gelatin, and 4-phenyl catechol, the resulting dried coating containing:

Addenda: Concentration -mg./ft. Magnetite 290 Ethyl cellulose 215 Gelatin 4-phenyl catechol 84 The magnetite particles utilized in the first and second layers described above were ball milled for 16 hours in toluene and thereafter mixed with the addenda of the re- After each transfer of the dried. The resulting photosensitive element was then exposed to a 20-second projection of a line original in a 1/1 camera with an f/ 22 lens opening, four No. 1 photoflood bulbs being used for illumination. exposed element was developed by immersing the exposed element for seconds in a 3% aqueous sodium carbonate bath at 82 F., and then unexposed and undeveloped silver halide stripped out by rolling a sheet of bond re- The resulting ceiving paper in contact with the developed emulsion on the element and peeling oif the receiving sheet. The resulting matrix was afiixed in a multilith press, wetted with the organic solvent, 2-(2-butoxy-ethoxy) ethyl acetate, and a plurality of prints made having printed characters with high magnetic permeability. The present process thus can be utilized to print magnetic characters of the type utilized'for printing such information as account numbers and branch bank numbers on negotiable instruments and the like.

In its broadest scope, the photoelement described herein comprises a photographic support coated with an organic solvent soluble polymer layer containing a pigment of high magnetic permeability overcoated with an organic solvent soluble polymer :layer containing a pigment of high magnetic permeability, gelatin, and a tanning developing agent. Over this latter layer is coated a photographic unhardened gelatino-silver halide emulsion.

The present invention thus provides a new and useful photosensitive element particularly adapted for the photomechanical duplication of positive images.

The invention has been described in considerable detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and asdefined in the appended claims.

I claim:

1. The process for preparing a printing matrix with a photosensitive element having a support, a polymer-containing layer comprising an organic oleophilic polymer compatible with a silver halide emulsion and soluble in an organic solvent, at least as immiscible in water as n-butanol, containing dispersed therein a gelatin tanning silver halide developing agent and at least one photographically inert pigment, and coated over said polymercontaining layer a photographic unhardened gelatinosilver halide emulsion layer, which comprises exposing said gelatino-silver halide emulsion layer from the emulsion layer side of said element and forming a latent image therein, developing said latent image to form a hardened gelatino-silver resist negative image area in said gelatinosilver halide emulsion layer by activating said tanning developing agent in said polymer-containing layer with an aqueous alkaline solution, pressing in contact with the resulting developed gelatino-silver halide emulsion layer a receiving element having an absorbent surface, separating said receiving element from said developed gelatinosilver halide emulsion layer and transferring substantially all unexposed and undeveloped gelatino-silver halide emulsion from said developed gelatino-silver halide emulsion layer to said receiving element leaving exposed to the surface of the resulting printing matrix said polymer-containing layer as a positive image area.

2. The process for preparing a printing matrix with a photosensitive element having a support, a polymer-containing layer comprising an organic oleophilic polymer compatible with a silver halide emulsion and soluble in an organic solvent, at least as immiscible in water as n-butanol, and gelatin at a concentration of about 10% to 40% based on the combined weight of the oleophilic polymer and the gelatin, a dihydroxy diphenyl gelatin tanning silver halide developing agent and at. least one photographically inert pigment being dispersed in said layer, and coated over said polymer-containing layer a photographic unhardened 'gelatino-silver halide emulsion layer at a coverage of about 50 mg. to mg.of gelatin per square foot, which comprises exposing from the emulsion layer side of said element said gelatino-silver halide emulsion layer and forming a latent image therein, developing said latent image to form a hardened gelatino-silver resist negative image area in said gelatino-silver halide emulsion layer by activating said tanning developing agent in said polymer-containing layer with an aqueous alkaline solution, pressing in contact with the resulting developed gelatino-silver halide emulsion layer areceiving element having an absorbent surface, separating said receiving element from said developed gelatino-silver halide emulsion layer and transferring substantially all unexposed and undeveloped gelatino-silver halide emulsion from said developed gelatino-silver halide emulsion layer to said receiving element leaving exposed to the surface of the resulting printing matrix said polymer-containing layer as a positive image area.

3'. A process as described in claim 2 wherein the organic solvent-soluble oleophilic polymer is a cellulose ether.

4. A process as described in claim 2 wherein the organic solvent-soluble oleophilic polymer is ethyl cellulose.

5. A process as described in claim 2 wherein at least one of the inert pigments is a magnetic pigment.

6. The process for preparing a printing matrix with a photosensitive element having a support, a first sublayer comprising an organic polymer compatible with a sliver halide emulsion and soluble in an organic solvent, at least as immiscible in water as n-butanol, containing dispersed therein a dihydroxy. diphenyl gelatin .tanning silver halide developing agent and at least one photographically inert pigment, a second sublayer coated over said first sublayer comprising gelatin and said organic solvent-soluble oleophilic polymer containing about 10% to 40% by weight of gelatin based on the combined weight of the gelatin and organic solvent-soluble oleophilic polymer, a dihydroxy diphenyl gelatin tanning silver halide developing agent and at least one photographically inert pigment being dispersed in said second sublayer, and coated over said second sublayer a photographic unhardened gelatino-silver halide emulsion layer at a coverage of about 50 mg. to 150 mg. of gelatin per square foot, which comprises exposing from the emulsion layer side of said element said gelatino-silver halide emulsion layer and forming a latent image therein, developing said latent image .to form a hardened gelatino-silver resist negative image area in said gelatino-silver halide emulsion layer by activating said tanning developing agent in the said sublayers with an aqueous alkaline solution, pressing in contact with the resulting developed gelatino-silver halide emulsion layer a receiving element having an absorbent surface, separating said receiving element from said developed gelatino-silver halide emulsion layer and transferring substantially all unexposed and undeveloped gelatino-silver halide emulsion from said developed gelatino-silver halide emulsion layer to said receiving element leaving exposed to the surface of the resulting printing matrix said second sublayer: as a positive image area.

7. A process as described in claim 6 wherein the organic solvent-soluble oleophilic polymer is a cellulose ether.

8. A process as described in claim 6 wherein the organic solvent-soluble oleophilic polymer is ethyl cellulose.

9. A process as described in claim 6 wherein'the substrate contains a magnetic pigment.

10. The process for preparing a printing matrix with a photosensitive element having a support, a sublayer comprising gelatin and ethyl cellulose containing about 10% to 40% by weight of gelatin based on the combined weight of the ethyl cellulose and the gelatin, a dihydroxy diphenyl gelatin tanning silver halide developing agent and particulate carbon being dispersed in the said sublayer and coated over said sublayer a photographic unhardened gelatino-silver chloride emulsion layer at a coverage of about 50 mg. to 150 mg. of gelatin per square foot, which comprises exposing from the said emulsion layer side of said element said gelatino-silver chloride emulsion layer and forming a latent image therein, developing said latent image to form a hardened gelatino-silver resist negative image area in said gelatino-silver chloride emulsion layer by activating said tanning developing agent in said sublayer by immersing said photosensitive element in an aqueous alkaline solution, pressing in contact with the resulting developed gelatino-silver chloride layer a receiving element having an absorbent surface, separating said receiving element from said developed gelatino-silver chloride emulsion layer and transferring substantially all unexposed and undeveloped gelatino-silver chloride emulsion from said developed gelatino-silver halide emulsion layer to said receiving element leaving exposed to the surface of the resulting printing matrix said sublayer as a positive image area.

11. A process as described in claim wherein the tanning developing agent is 4-phenyl catechol.

12. The process for preparing a printing matrix with a photosensitive element having a support, a first sublayer comprising ethyl cellulose containing dispersed therein a dihydroxy diphenyl gelatin tanning silver halide developing agent and magnetic particles, at second sublayer coated over said first sublayer comprising gelatin and ethyl cellulose containing about -10% to 40% by weight of gelatin based on the combined weight of the ethyl cellulose and the gelatin, a dihydroxy diphenyl gelatin tanning silver halide developing agent and magnetic particles being dispersed in said second sublayer, and coated over said second sublayer a photographic nnhardened gelatino-silver chloride emulsion layer at a coverage of about 50 mg. to 150 mg. of gelatin per square foot, which comprises exposing vfrom the emulsion layer side of said element said gelatinosilver chloride emulsion layer and forming a latent image therein, developing said latent image to form a hardened gelatino-silver resist negative image area in said gelatinosilver chloride emulsion layer by activating said tanning developing agent in the said sublayers by immersing said photosensitive element in an aqueous alkaline solution, pressing in contact with the resulting developed gelatinosilver chloride layer a receiving element having an absorbent surface, separating said receiving element from said developed gelatino-silver chloride emulsion layer and transferring substantially all unexposed and undeveloped gelatino-silver chloride emulsion from said developed gelatino-silver halide emulsion layer to said receiving element leaving exposed to the surface of the resulting printing matrix said sublayer as a positive image area.

13. A process as described in claim 12 wherein the tanning developing agent is 4-phenyl :catechol.

14. A photosensitive element comprising a support, a polymer-containing layer comprising an organic oleophilic polymer compatible with a silver halide emulsion and soluble in an organic solvent, at least as immiscible in water as n-butanol, containing dispersed therein a gelatin tanning silver halide developing agent and at least one photographically inert pigment, and coated over said polymer-containing layer a photographic unhardened gelatino-silver halide emulsion layer.

15. A photosensitive element comprising a support, a polymer-containing sublayer comprising an organic oleophilic polymer compatible with a silver halide emulsion and soluble in an organic solvent, at least as immiscible in water as n-butanol, and gelatin at a concentration of about 10% to 40% based on the combined weight of the oleophilic polymer and the gelatin, a dihydroxy diphenyl gelatin tanning silver halide developing agent and at least one photographically inert pigment being dispersed in said sublayer, and coated over said polymer-containing sublayer a photographic unhardened gelatino-silver halide emulsion layer at a coverage of about 50 mg. to mg. of gelatin per square foot.

16. A photosensitive element as described in claim 15 wherein the organic solvent-soluble oleophilic polymer is a cellulose ether.

17. A photosensitive element comprising a support, a first sublayer comprising an organic polymer compatible with a silver halide emulsion and soluble in an organic solvent, at least as immiscible in water as n-butanol, containing dispersed therein a dihydroxy diphenyl gelatin tanning silver halide developing agent and at least one photographically inert pigment, a second sublayer coated over said first sublayer comprising gelatin and said organic solvent-soluble oleophilic polymer containing about 10% to 40% by weight of gelatin, based on the combined weight of the gelatin and organic solvent-soluble oleophilic polymer a dihydroxy diphenyl gelatin tanning silver halide developing agent and at least one photographically inert pigment being dispersed in said second sublayer, and coated over said second sublayer a photographic unhardened gelatino-silver halide emulsion layer at a cover- .age of about 50 mg. to 150 mg. of gelatin per square foot.

18. A photosensitive element as described in claim 17 wherein the organic solvent-soluble oleophilic polymer is a cellulose ether.

19. A photosensitive element comprising a support, a sublayer comprising gelatin and ethyl cellulose containing about 10% to 40% by weight of gelatin based on the combined weight of the ethyl cellulose and the gelatin, a dihydroxy diphenyl gelatin tanning silver halide developing agent and at least one pigment selected from the class consisting of magnetic particles and particulate carbon being dispersed in said sublayer, and coated over said sublayer a photographic unhardened gelatino-silver chloride emulsion layer at a coverage of about 50 mg. to 150 mg. of gelatin per square foot.

20. A photosensitive element comprising a support, a first sublayer comprising ethyl cellulose containing dispersed therein a dihydroxy diphenyl gelatin tanning silver halide developing agent and at least one pigment selected from the class consisting of magnetic particles and particulate carbon, a second sublayer coated over said first sublayer comprising gelatin and ethyl cellulose containing about 10% to 40% by weight of gelatin based on the combined weight of the ethyl cellulose and the gelatin, a dihydroxy diphenyl gelatin tanning silver halide developing agent and at least one pigment selected from the class consisting of magnetic particles and particulate carbon being dispersed in said second sublayer, and coated over said second sublayer a photographic unhardened gelatinosilver chloride emulsion layer at a coverage of about 50 mg. to 150 mg. of gelatin per square foot.

References Cited by the Examiner UNITED STATES PATENTS 2,409,564 10/ 1946 Heinecke et al. 9683 3,146,104 8/1964 Yackel et a1. 9=628 3,152,898 10/1964 Hepher et al 96-28 3,157,506 ll/ 1964 Gates et al. 9 687 NORMAN G. TORCHIN, Primary Examiner. I. H, RAUBITSCHEK, Assistant Examiner. 

1. THE PROCESS FOR PREPARING A PRINTING MATRIX WITH A PHOTOSENSITIVE ELEMENT HAVING A SUPPORT, A POLYMER-CONTAINING LAYER COMPRISING AN ORGANIC OLEOPHILLIC POLYMER COMPATIBLE WITH A SILVER HALIDE EMULSION AND SOLUBLE IN AN ORGANIC SOLVENT, AT LEAST AS IMMISCILBE IN WATER AS N-BUTANOL, CONTAINING DISPERSED THEREIN A GELATIN TANNING SILVER HALIDE DEVELOPING AGENT ANS AT LEAST ON PHOTO GRAPHICALLY INERT PIGMENT, AND COATED OVER SAID POLYMERCONTAINING LAYER A PHOTOGRAPHIC UNHARDENED GELATINOSILVER HALIDE EMULSION LAYER, WHICH COMPRISES EXPOSING SAID GELATINO-SILVER HALIDE EMULSION LAYER FORM THE EMULSION LAYER SIDE OF SAID ELEMENT AND FORMING A LATENT IMAGE THEREIN, DEVELOPING SAID LATENT IMAGE TO FROM A HARDENED GELATINO-SILVER RESIST NEGATIVE IMAGE AREA IN SAID GELATINOSILVER HALIDE EMULSION LAYER BY ACTIVATING SAID TANNING DEVELOPING AGENT IN SAID POLYMER-CONTAINING LAYER WITH AN AQUEOUS ALKALINE SOLUTION, PRESSING IN CONTACT WITH THE RESULTING DEVELOPED GELATINO-SILVER HALIDE EMULSION LAYER A RECEIVING ELEMENT HAVING AN ABOSRBENT SURFACE, SEPARATING SAID RECEIVING ELEMENT FROM SAID DEVELOPED GELATINOSILVER HALIDE EMULSION LAYER AND TRANSFERRING SUBSTANTIALLY ALL UNEXPOSED AND UNDEVELOPED GELATINO-SILVER HALIDE EMULSION FROM SAID DEVELOPED GELATINO-SILVER HALIDE EMULSION LAYER TO SAID RECEIVING ELEMENT LEAVING EXPOSED TO THE SURFACE OF THE RESULTING PRINTING MATRIX SAID POLYMER-CON TAINING LAYER AS A POSITIVE IMAGE AREA.
 14. A PHOTSENSITIVE ELEMENT COMPRISING A SUPPORT, A POLYMER-CONTAINING LAYER COMPRISING AN ORGANIC OLEOPHILIC POLYMER COMPATIBLE WITH A SILVER HALIDE EMULSION 